Formation of water droplets on the surface of cold water pipes in air conditioning systems. (Condensation on Chilled Water Pipes)
It is a common problem in air conditioning systems. Especially in areas where High relative humidity, such as Thailand

🔍 Causes of water droplets

The formation of water droplets is a result of condensation of water vapor in the air (Condensation) when the water vapor in the air comes into contact with the surface of the cold water pipe at a temperature lower than the dew point of the air in that area.
 • The cold water pipe has a low temperature (e.g. 7°C).
 • The air around the pipe has high humidity.
 • The dew point of air may be 15–20°C.
 • When the water vapor in the air comes in contact with the cooler surface of the pipe, It will condense into water droplets.

⚠️ Effects of water droplets
 • Water drips onto the floor, making the floor slippery. There was an accident.
 • Destroy ceilings, walls, or decorative materials.
 • Stimulates fungal growth.
 • Reduces the efficiency of the air conditioning system.

✅ How to fix and prevent

1. Insulate cold water pipes correctly.
 • Use closed cell insulation such as PE Foam or PU Foam.
 • Choose the appropriate thickness, such as:
 • If the water temperature is cold 6–8°C → use insulation thickness 19–25 mm.
 • The insulation must have no gaps and no steam leaks.

2. Seal the joints tightly.
 • Use insulating tape or specialized glue (Adhesive) to seal the joints.
 • Seal all leak points where steam can penetrate.

3. Install the vapor barrier (Vapor Barrier).
 • Used as a protective layer to prevent water vapor from penetrating the insulation.
 • Recommended use of aluminum foil. or specific moisture-proof materials

4. Improve ventilation.
 • Increase ventilation to reduce humidity in the area.
 • May install ventilation fans or humidity control systems. (Dehumidifier)

5. Check the humidity in the engine room or ceiling.
 • Control Relative Humidity not to exceed 60%.
 • Install temperature and humidity meters. to plan protection

📌 Summary

The formation of water droplets on the surface of cold water pipes is caused by moisture in the air coming into contact with the surface at a temperature lower than the dew point. The important solution is Choose the correct insulation Install firmly and prevent water vapor from penetrating. Including controlling humidity in the surrounding area